1. Field of the Invention
The present invention relates to a punching tool provided with a tool identification medium and a punch press provided with a tool identification medium reader.
2. Prior Art
In a punch press for performing punching operation on a sheet workpiece, such as sheet metal, a variety of punches and dies (i.e. tools) are provided in accordance with the shapes of holes to be made in the workpiece. In a turret punch press, these punches and dies are mounted on upper and lower turrets each rotatably supported by a machine frame. The turrets are adapted to be rotated to selectively bring a desired punch-and-die pair to a predetermined working position. In another punch press, a variety of punches and dies are stored in a tool magazine, and a desired punch-and-die pair is selected from the magazine and supplied to a working position of the punch press.
To manage or supervise such a large number of punches and dies, it is disclosed in prior arts to attach tool identification mediums to respective punches and dies and to detect the same identification mediums by a suitable detection device. For example, JP63-174733A discloses a punch press provided with a tool changing device. In the punch press, tool information for distinguishing upper tool and lower tool, and tool-pair information for speciying the upper and lower tools as a upper-and-lower tool pair are stored. Further, in this press, storage positions in the tool magazine where the upper and lower tools are accommodated are stored in the memory while being correlated to the tool-pair information. During the operation of the press, desired upper and lower tools are selected and taken out from the magazine on the basis of such tool-pair information, so that the tools are changed with old tools on the punch press. The tool-pair information includes tool shape information, tool size information and tool clearance information. The tool information includes a tool manufacturing number and a tool manufacturing date. Such information may be represented by bar codes that is provided on the surface of the tools to be read by a bar code scanner.
However, conventional punches and dies have very small area for bearing the identification medium, so that the medium representing complex information cannot be attached to the tools.
Further, the conventional system has the following problem. That is, when tools are stored in the tool magazine or mounted on the turret, potential operator's errors of storing the tools in an erroneous position in the magazine or of mounting tools in an erroneous tool mounting section on the turret so as to face an erroneous direction cannot be detected.
Further, a conventional system includes another problem that when a plurality of punch presses are used, tools on the punch presses cannot be searched because the plurality of the presses are not uniformly managed or supervised therein.
Further, a conventional system has a problem that a control program for a punch press were prepared without taking account of the tools mounted on the turret or stored in the tool magazine, so that working time was wasted for mounting necessary tools before actual punching operation.